«Calcaires à Thalassinoides»
Representation and status
- Color CMYK
- N/A
- Color RGB
- R: 125 G: 125 B: 125
- Rank
- Beds (Submember)
- Validity
- Unit is not in Use
- Status
- local name (informal)
Nomenclature
- Deutsch
- «Thalassinoides-Kalk»
- Français
- «Calcaires à Thalassinoides»
- Italiano
- «Calcare a Thalassinoides»
- English
- «Thalassinoides Limestone»
- Origin of the Name
-
Namengebendes Spurenfossil: Thalassinoides
- Historical Variants
-
Thalassinoides Limestone (Jank 2004 p.17, Jank et al. 2006), Calcaires à Thalassinoides (Comment et al. 2015)
Description
- Thickness
- Environ 30 m (Jank et al. 2006c, Comment et al. 2015).
Components
- trace fossils
Age
- Age at top
-
- Early Kimmeridgian
- Note about top
-
zone à Platynota / zone à Baylei pars.
- Age at base
-
- Early Kimmeridgian
- Note about base
-
zone à Platynota / zone à Baylei pars.
Palaenography and tectonic
-
- Malm of the Jura Mountains
- Tectonic unit (resp. main category)
-
-
Jura
:
Juragebirge
-
Jura
:
- Kind of protolith
-
- sedimentary
- Conditions of formation
-
Base de séquence transgressive.
- Metamorphism
- non metamorphic
References
- Definition
-
(2006) :
A calibrated composite section for the Late Jurassic Reuchenette Formation in northwestern Switzerland (?Oxfordian, Kimmeridgian sensu gallico, Ajoie-Region) Eclogae geol. Helv. 99, 175-191
Thalassinoides Limestone (≈30 m) (Plate 1, a):
The Reuchenette Formation starts with monotonous, thick- to massive-layered (m-thick), well-bedded, bioturbated, grey, micritic limestones with some bioclasts and reddish brown or greyish, coarse-grained, pseudo-oolitic (mainly rounded intraclasts and peloids) pockets, patches and strings within a micritic matrix. Generally, macrofossils are rare. Thin to thick-bedded layers fracture conchoidally and commonly contain abundant Thalassinoides. These burrows are often filled with the coarse-grained pseudo-oolitic material mentioned above. Between 22 m and 30 m (composite section; Fig. 4) several conspicuous horizons with Thalassinoides are filled with coarse spary cement (beds VAT-150, VAT-20, COE-240, COE-170, COE-180, VAB-40, VAB-30, RAS-25; see Fig. 4). Bed surfaces are often iron stained, occasionally bored and biogenically encrusted by oysters. About 9 m below the upper boundary of this interval, a 6–7 meters thick, white, chalky limestone with oncoids and coral clasts occurs within the monotonous, grey, micritic interval (e.g. beds RAS-45 to RAS-48; Fig. 4). In La Rasse another 3–4 m thick white layer is visible, intercalated into the grey limestones (beds RAS-57 to RAS- 60), as well. In Coeuve the top few meters bear a stromatolite layer.